Dinosaur tells the story of Aladar, an iguanodon who is separated from his own kind and raised by a clan of lemurs. When a meteor shower destroys their home, Aladar and his family follow a herd of dinosaurs heading for the safety of the "nesting grounds." Together they must stand strong amidst food and water shortages, the threat of Carnotaur attacks, and Aladar's run-ins with the herd's stubborn leader, Kron.